TW200305632A - Material for organic electroluminescent element and organic electroluminescent element employing the same - Google Patents

Abstract

A material for organic electroluminescent elements which comprises a compound comprising a group comprising a carbazole skeleton and bonded thereto a cycloalkyl or m-phenylene group; an organic electroluminescent element which comprises a negative electrode, a positive electrode, and sandwiched therebetween one or more organic thin-film layers, in which at least one of the organic thin-film layers contains the material for organic electroluminescent elements. The electroluminescent element, which employs that material, has a high color purity and emits a blue light.

Description

200305632 (1) 发明. Description of the invention [Technical field to which the invention belongs] The present invention relates to materials for organic electroluminescent devices and organic electroluminescent devices (organic EL devices) using the materials, and particularly to high color purity and generation. Blue light-emitting organic EL element. [Prior Art] Organic EL devices using organic substances are considered as solid-light-emitting, inexpensive, and large-area full-color displays, and many studies have been conducted. Generally, an organic EL element is composed of a light-emitting layer and a pair of opposing electrodes sandwiching the layer. When an electric field is applied between two electrodes, the luminescence of an organic EL element is when electrons are injected from the cathode side and holes are injected from the anode side. In the light-emitting layer, the electrons and holes are recombined to generate an excited state. When the excited state returns to the ground state, the energy is light. Phenomenon of morphological release. Examples of the light-emitting material include chelate complexes such as ginseng (8-quinoline) aluminum complexes, coumarin derivatives, tetraphenylbutadiene derivatives, bisstyrylpropyne derivatives, and oxydiazepines. Light-emitting materials such as molybdenum derivatives are known. These can emit light in the visible light range from blue to red, and are expected to be used for color display elements (for example, Japanese Patent Laid-Open No. 8-23 965 5, Japanese Patent Laid-Open No. 7_ 1 3 8 5 6 1 and JP-A 3-200289 etc.). Although organic EL element displays have recently been put into practical use, full-color display elements are still under development. In particular, there is a need for an organic EL element that has high color purity and high luminous efficiency and produces blue-based light emission. -6- (2) (2) 200305632 In order to solve the above-mentioned problems, for example, Japanese Patent Application Laid-Open No. 8-1226 discloses a device using a blue light-emitting material of a phenylanthracene derivative. The phenylanthracene derivative is used as a blue light-emitting material, and is generally used as a laminate of a para- (8-quinolinol) aluminum (Alg) complex and the blue material layer, but the luminous efficiency, lifetime, blue Color purity is not as good as practical level. Japanese Patent Application Laid-Open No. 2000-1-28462 discloses a blue light-emitting element in which an amine-based aromatic compound is used in a light-emitting layer, but has a low light-emitting efficiency of 2 to 4 cd / A. Japanese Patent Application Laid-Open No. 200 1-1 60489 discloses that an element in which an azafluoranthene compound is added to a light-emitting layer generates yellow to green light, and cannot reach blue light with extremely high color purity. [Summary of the Invention] The present invention has been made to solve the above-mentioned problems, and provides a material for an organic EL element that emits blue light with high color purity and an organic EL element using the material. In order to solve the above-mentioned problems, the present inventors have carefully studied and found that a compound having a carbazole skeleton bonded to a cycloalkyl or m-phenylene group as a main material can be used to obtain an organic EL device having a blue purity. The present invention has been completed. In other words, the present invention provides a material for an organic electroluminescent device composed of a compound represented by the following general formula (1) or (2). (Cz-) nL (1)

Cz (-L) m (2) (3) 200305632 [where Cz is a group formed by a compound having a carbazole skeleton represented by the following (A) may be substituted, and L is a substituted or unsubstituted carbon atom A cycloalkyl group having a number of 5 to 30, or an aromatic ring group having 6 to 30 carbon atoms having a substituted or unsubstituted carbon atom represented by the following (B), n and m are integers of 1 to 3, respectively;

(X is a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, a substituted or unsubstituted aryl alkyl group having 7 to 40 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 40 carbon atoms )

(P is an integer from 1 to 4). The invention provides an organic electro-optic light-emitting element, which is an organic electro-optical light-emitting element with an organic thin film layer composed of a single layer or multiple layers sandwiched between a cathode and an anode, and is characterized in that at least one of the organic thin film layers contains the foregoing Material for organic electroluminescent device. In the organic thin film layer, the light-emitting layer, the electron transport layer, or the hole transport layer may contain the above-mentioned material for an organic EL element. [Implementation content] The material for the organic EL element of the present invention is represented by the following general formula (1) or -8-(4) (4) 200305632

2) It is composed of the compound shown. (Cz_) nL CZ (-L) m [wherein Cz is a group formed by a compound having a carbazole skeleton represented by the following (A), which may be substituted, arylcarbazolyldiyl, diaryl Carbazole diyl °

Examples of the substituent of CZ include halogen atoms such as chlorine, bromine and fluorine, indolyl, carbazolyl, cyano, silyl, trifluoroaryl, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or Unsubstituted aralkyl, substituted or unsubstituted aryloxy, substituted or unsubstituted alkoxy, and the like. # Is preferably a fluorine atom, a p-phenylene group, a trifluoromethyl group, or a perfluoroaryl group. n and m are integers of 1 to 3, respectively. X is a substituted or unsubstituted carbon atom having 6 to π & 丄 丄, a substituted or unsubstituted aralkyl group having 7 $ 40 carbon atoms, or a substituted or unsubstituted carbon atom having 6 to Aryloxy of 40. Examples of the aryl group having 6 to 40 carbon atoms include phenyl, zirconium, anthracenyl, anthryl, phenanthryl, butanyl, fluorenyl, fluorenyl, biphenyl, diphenyl ~ benzyl, phenylanthracene And fluoranthryl, etc. Among them, phenyl, naphthyl, biphenyl, -9- (5) 200305632 triphenyl, fluorenyl, and phenylanthryl are preferred. Lord of carbon number 7 to 40: household: a imitation 丨 & square alkyl groups such as benzyl, methylbenzyl, cinnamyl, Q-ethylbenzyl, ~ α methylbenzyl, Methylbenzyl, 4-ethylfluorenyl, 2-r-butanyl butanyl, it is a radical, 4-n-octylbenzyl, naphthylmethyl, monobenzylmethyl, etc. It preferably has a middle group, a methyl benzyl group, and a diphenylmethyl group. For example, a benzoyl group having 6 to 40 + carbon atoms includes a phenoxy group, a tolyloxynaphthyl group, an enyl group, a succinyl group, and a bisoxy group, a bibenyloxy group, a fluorantheneoxy group, and a third phenoxy group. Phenanthryloxy, etc., should preferably be Benzoyl, tolyloxy, biphenyloxy. _ Substituents such as substituted or unsubstituted alkyl, substituted or unsubstituted substituted or unsubstituted aralkyl, substituted or unsubstituted aryloxy 'substituted or unsubstituted alkoxy, substituted or unsubstituted heteroaromatic hetero Ring base and so on. Among them, fluorine atom, p-phenylene group, benzyl group, phenoxy group, carbazolyl group and the like are preferably substituted or unsubstituted cycloalkyl groups having 5 to 30 carbon atoms, or -P * '_ | i . R & (B) represents a substituted or unsubstituted carbon ring group having 6 to 30 carbon atoms and is preferably a cyclohexyl group, a norbornenyl group, or an adamantyl group. The substituent of L is, for example, the same as the aforementioned C z.

(B) An integer of 1 to 4, ideally 1 to 2) 〇 The compound represented by the general formula (〗) or (2) of the present invention is more preferably -10- (6) (6) 200305632 3) The compound represented by any one of (1) to (1) is represented by one L —Cz (n ~ 2) (3) 〇-— Cz—Cz I (n-3) (4) L Cz—- L — Cz — Cz (n-3) (5) Cz — Cz—Cz — L (n = 3) (6) L-Cz ~ L (m = 2) (7) L—L —Cz (m = 2) (8) L -Cz—L i (m = 3) (9) LL—L—Cz—L (m = 3) (10) Cz—L—L—L (m = 3) (11) General formula of the present invention (1 Specific examples of the compound represented by) are limited to those exemplified.

-11-(7) 200305632

-12- (8) (8) 200305632 Specific examples of the compound represented by the general formula (2) of the present invention are as follows, but are not limited to these exemplified compounds.

The singlet energy gap of the compound represented by the general formula (1) or (2) of the present invention is 2.8 to 3.8 eV, preferably 2.9 to 3.6 eV. -13- 200305632 〇) The organic el element of the present invention is an organic EL element in which an organic thin film layer composed of a single layer or multiple layers is sandwiched between a cathode and an anode, and at least one layer of the organic thin film layer contains A material for an organic EL device composed of the compound of the general formula (1) or). The light-emitting layer of the organic EL element preferably contains a material for an organic EL element composed of the compound of the general formula (1) or (2). The organic EL device of the present invention emits blue light, and contains those having high purity (0.12, 0.10) to (0.17, 0.20). This is because the material for an organic EL element composed of the compound of the general formula (1) or (2) has a wide energy gap. The organic EL device of the present invention desirably emits light by triplet excitation or multiple-state excitation in a triplet state or more. The material for the organic EL element of the present invention is preferably the main material of the organic EL element. This main material refers to the ability to inject holes and electrons, transport holes and electrons, and then combine to have the function of generating fluorescence. The compound of the general formula (1) or (2) of the present invention has a high single-state energy gap of 2.8 to 3.8 eV and a triplet energy gap of 2.5 to 3.3 eV. Therefore, it can be used as an organic main material for a phosphor device. Phosphorescent element refers to a substance containing a higher luminous intensity than other substances due to the transition from the energy state of the triplet level to the base singlet state. A phosphorescent substance such as a compound is an organic electric field light-emitting element using phosphorescence. In the light-emitting layer of the organic EL element, the singlet excitons and triplet excitons are mixed in the generated molecular excitons, and the singlet excitons and triplet excitons are generally 14-200305632 do) in a ratio of 1: 3. More triplet excitons can be generated. In addition, in the case of a general fluorescent organic EL element, excitons participating in light emission are singlet excitons, and triplet excitons are non-luminous. Therefore, the triplet exciton is eventually consumed in a thermal state, and only the singlet exciton with a lower yield emits light. Therefore, the organic EL element uses the energy generated by the recombination of holes and electrons, and the energy transferred to the triplet exciton is a large loss. Therefore, the compound of the present invention is used in a phosphor device, and the energy of the triplet exciton can be used for light emission, so that the light-emitting efficiency using a fluorescent device can be three times as high. When the compound of the present invention is used in a light emitting layer of a phosphorescent element, it has an excitation with a higher energy state than the excited triplet state of the phosphorescent organometallic complex containing a metal selected from Groups 7 to 11 contained in the layer Triplet level, and provides a stable film shape, with high glass transition temperature (Tg: 80 ~ 160 ° C), can effectively transport holes and / or electrons, and is electrochemically and chemically stable when manufactured or used It is difficult to produce impurities that become a light collector or disappear. The hole injection layer, the electron injection layer, and the hole barrier layer may contain the compound of the present invention. The phosphorescent compound and the compound of the present invention may be used in combination. As described above, the organic EL device of the present invention is a device in which a single or multiple organic thin film layers are formed between an anode and a cathode. In the single-layer type, a light-emitting layer is provided between the anode and the cathode. The light-emitting layer contains a light-emitting material, and may also contain a hole-injection material or an electron-injection material in order to transport the hole injected from the anode or the electron injected from the cathode to the light-emitting material. In addition, the luminescent material has both extremely high fluorescence efficiency, high hole-transporting ability, and electron-transporting energy. -15- (11) (11) 200305632 Force ′ can form a uniform film. The multilayer organic EL element includes (anode / hole injection layer / light emitting layer / cathode), (anode / light emitting layer / electron injection layer / cathode), (anode / hole injection layer / light emitting layer / electron injection layer / Cathode) and so on. When necessary, in addition to the compound of the general formula (1) or (2) in the light-emitting layer, known main materials, light-emitting materials, doped materials, hole injection materials, and electron injection materials may be used, or they may be used in combination. . The organic EL element has a multi-layer structure to prevent the brightness or life from being reduced due to rapid cooling. Other doping materials can be used to improve the luminous brightness and luminous efficiency, or other doping materials can be used in combination to help the luminescence and luminescence. Or luminous efficiency. In addition, the hole injection layer, the light emitting layer, and the electron injection layer of the organic EL device of the present invention may be formed by two or more layer structures. At this time, the situation of the hole injection layer: the layer injected into the hole by the electrode is called the hole injection layer, and the layer that receives the hole from the hole injection layer and transports the hole to the light-emitting layer is called the hole transport layer. Similarly, in the case of an electron injection layer: a layer in which electrons are injected from an electrode is referred to as an electron injection layer, and a layer that receives electrons from the electron injection layer and transports electrons to the light emitting layer is referred to as an electron transport layer. These layers are selected and used depending on factors such as the energy level of the material, heat resistance, and adhesion to the organic thin film layer or metal electrode. In the organic EL device of the present invention, the electron transport layer and the hole transport layer may contain a material for an organic EL device composed of a compound of the general formula (1) or (2). The compounds of the general formula (1) or (2) of the present invention and the light-emitting materials or main materials that can be used in organic-16- (12) (12) 200305632 thin film layers include, for example, anthracene, naphthalene, phenanthrene, cerene, dian, Halobenzene, fluorescein, fluorescein 'fluorene, phthalocyanine, fluorene naphthalate, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, aldehyde azide, bisbenzoxazoline , Bistyrene, pyrazine, cyclopentadiene, quinoline metal complex, aminoquinoline metal complex, benzoquinoline metal complex, imine, diphenylethylene, vinyl anthracene, Diaminoanthracene, diaminobenzazole, pyran, thiane, polymethyne, merocyanine, imidazole chelated oxygenates, fluorene, rubrene, & derivatives and fluorescent pigments Etc., but not limited to these materials. Fluorescent materials are more preferably phosphorescent organometallic complexes from the viewpoint of improving the external quantum efficiency of the device. The metal atoms of the organometallic complexes include, for example, ruthenium, germanium, palladium, silver, chains, hungry, indium, Platinum 'gold. These organic metal complexes are preferably organic metal complexes represented by the following general formula (C).

(Wherein A1 represents a substituted or unsubstituted aromatic hydrocarbon ring group or an aromatic heterocyclic group, preferably phenyl, biphenyl, naphthyl, anthracenyl, thienyl, pyridine (J-denyl, quinoline) And isoquinolinyl, the aforementioned substituents include halogen atoms such as fluorine atom; alkyl groups having 1 to 30 carbon atoms such as methyl group and ethyl group; alkenyl groups such as vinyl group; methoxycarbonyl group and ethoxy group Carbonyl and other alkoxycarbonyl groups having 1 to 30 carbon atoms; methoxy, ethoxy and other carbon atoms having 1 to 30 carbon atoms-17- (13) (13) 200305632 oxygen; phenoxy, Aryloxy groups such as benzyloxy, alkylamino groups such as dimethylamino, diethylamino, fluorenyl groups such as ethylfluorenyl, haloalkyl groups such as trifluoromethyl, and cyano groups. A substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom forming a heterocyclic ring, preferably pyridyl, pyrimidinyl, pyrazinyl, benzothiazolyl, benzooxazolyl, benzimidazolyl, etc. , Quinolinyl, iso. Group, quinoxalinyl, azaphenanthryl, the foregoing substituents are, for example, the same as those listed. Φ A1 containing ring and A2 containing ring can form a condensed ring, for example, there is 7, 8-benzoquine Q is a metal selected from Groups 7 to 11 of the periodic table, preferably ruthenium, _, palladium, silver, chain, hungry, indium, platinum, gold. L is a bidentate ligand, compared with The preferred one is a diketone ligand or pyromellitic acid selected from the group consisting of acetopropyl propionate and $. M and η are the integers shown in Table 75 when Q is-* valent metal, η == 2, 0, Q When it is a trivalent metal, n = 3 and m = 0, or n = 2 and m = l) _ The specific details of the organometallic complex shown by the general formula (C) above are not limited to these organic compounds. Metal complexes. -18- (14) 200305632

-19- (15) 200305632

(K-12) -20-(16) 200305632

(K-15)

PH3 O ^ Q 〇-c ch3

(K-) 7)

-21 (17) 200305632 (K-JS)

-22- (18) (18) 200305632 The hole injection material is ideal for the ability to transport holes, has the hole injection effect from the anode, and has excellent hole injection effect for the light-emitting layer or light-emitting material, preventing the light-emitting layer from A compound that excites the generated exciton to an electron injection layer or an electron injection material and has an excellent ability to form a thin film. Specific examples include phthalocyanine derivatives, naphthalocyanine derivatives, porphyrin derivatives, oxazoles, oxadiazoles, triazoles, imidazoles, imidazolones, imidazole sulfur, pyrazolines, pyrazolones, tetrahydroimidazoles, Samarium, fluorenyl amidine, polyarene, stilbene, butadiene, benzidine triphenylamine, styrylamine triphenylamine, diamine triphenylamine, and their derivatives, and polyvinylcarbazole, polysilane, conductive Polymer materials such as polymer, but are not limited to these hole injection materials. Among these hole injection materials, the more effective hole injection materials are aromatic tertiary amine derivatives or phthalocyanine derivatives. Specific examples of the aromatic tertiary amine derivative include triphenylamine, tricresylamine, toluene diphenylamine, N, N'-diphenyl-N, N '-(3-methylphenyl) -1,1'-biphenyl -4,4'-diamine, N, N, N ,, N '-(4-methylphenyl) -1,1'-phenyl-4,4'-diamine, N, N, N ,, N '-(4-methylphenyl) -1,1'-biphenyl-4,4'-diamine, Ν, N'-diphenyl-N, N'-dinaphthyl-1 , 1'-biphenyl-4,4'-diamine, N, N '-(fluorenylphenyl) -N, N'-(4-n-butylphenyl) -phenanthrene-9,10-di Amines, N, N-bis (4-di-4-tolylaminophenyl) -4-phenylcyclohexane, etc., or oligomers or polymers having these aromatic tertiary amine skeletons, but not limited These aromatic tertiary amine derivatives. Specific examples of phthalocyanine (Pc) derivatives include H2Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, CIGaPc, CllnPc, CISnPc, Cl2SiPc, (HO) AlPc, (HO) GaPcPV, , MoOPc, GaPc-23-23 (19) (19) 200305632 0-GaPc and other phthalocyanine derivatives and naphthalocyanine derivatives, but are not limited thereto. The electron injection material is preferably capable of transporting electrons, has the effect of injecting electrons from the cathode, has an excellent electron injection effect on the light emitting layer or the light emitting material, and prevents excitons generated by the light emitting layer from moving to the hole injection layer, and Compound excellent in film-forming ability. Specifically, there are fluorene, anthrone dimethylmethane, bi-paraquinone, thiolated dioxygen, oxazole, oxodiazepine, triazole, imidazole, humic acid, D quinoxaline, sulfenylmethane, anthracene Quinonedimethane, anthrone and the like and derivatives thereof are not limited to these electron injection materials. Among these electron injection materials, the more effective electron injection materials are metal complexes or nitrogen-containing five-membered ring derivatives. Specific examples of metal complexes include lithium 8-hydroxyquinoline, zinc bis (8-hydroxyquinoline), bis (8-hydroxyquinoline) ketone, bis (8-hydroxyquinoline) manganese, and ginseng (8-hydroxy Quinoline) aluminum, ginseng (2-methyl-8-hydroxyquinoline) aluminum, ginseng (8-hydroxyquinoline) gallium, bis (10-hydroxybenzo [h] quinoline) beryllium, bis (10-hydroxyl Benzo [h] quinoline) zinc, bis (2-methyl-8-Dquinoline) gallium chloride, bis (2-methyl-8-Dquinoline) (o-cresol) gallium, bis (2 -Fluorenyl-8-quinoline) (1-naphthol) aluminum, bis (2-methyl-8-quinoline) (2-naphthol) gallium, etc., but not limited to these metal complexes. The nitrogen-containing five-membered ring derivative is preferably an oxazole, thiazole, oxadiazole, thiadiazole, or triazole derivative. Specifically, there are 2,5-bis (1-phenyl) -1,3,4-oxazole, dimethyl POPOO, 2,5-bis (1-phenyl) -1,3,4-thiazole , 2,5-bis (1-phenyl) · 1,3,4-oxadiazole, 2- (4'-third butylphenyl) -5- (4 ,,-biphenyl) -1 , 3,4-oxadiazole, 2,5-bis (1-naphthyl) -1,3,4-oxadiazole, 1,4-bis [2- (5-phenyl-24- (20) 200305632 oxydiazacenyl)] benzene, 1 '4-bis {[2- (cenelocene) -4-third butylbenzene], 2- (4-third butyl 4 ,, _ biphenyl)- 1,3,4-thiadiazole, 2,5-bis (:, 4-thiadiazole, 1,4-bis [2- (5-phenylthiadiazolyl 4, -third butylphenyl) ) -5- (4 "· biphenyl) -1, 5,5-bis (1-naphthyl) -1,3,4-triazole, 1,4-bistriazolyl)] benzene, etc., but not It is limited to this. In addition, the addition of an electron-accepting substance to the electron-injecting material can increase the charge-injection property. The anode of the organic EL element used in the present invention has a work function greater than 4 eV, which can be used. Carbon, cobalt, nickel, tungsten, silver, gold, platinum, palladium, etc. and their combined substrates, NESA-based Organic conductive resins such as oxythiophene of tin oxide, indium oxide, or polypyrrole, etc. It is ideal for females with a work function less than 4 eV. Lead, titanium, yttrium, lithium, ruthenium, manganese, aluminum, etc And its alloys. Representative examples of the alloy include magnesium / silver, magnesium / indium, lithium / aluminum, etc., but the ratio of gold is a ratio of the temperature, atmosphere, and vacuum of the evaporation source. When necessary, the anode and cathode can be divided into two The organic EL device of the present invention may have an inorganic compound layer between at least one of the organic thin film layers. Preferred inorganic compounds using the layer include alkali metal oxides, rare earth oxides, alkali metal halides, Alkaline earth phenyloxydiazaphenyl) -5- (I-naphthyl) -1,3)] benzene, 2- (3,4-triazole, 2 [2- (5-phenyl and electron injection Ideal material of electrical materials, vanadium, iron, gold, conductive materials such as magnesium, calcium, and tin used for ITO metal, but not limited to this. Not limited to this. For all controls, select the above layer structure First electrode and inorganic compounds, alkaline earth oxide halides, rare earths- 25- (21) (21) 200305632 Halides, SiOx, AIOχ, SiNx, SiON, A10N, GeOx, LiOx, LiON, TiOx, TiON, TaOx, TaON, TaNx, C and other oxides, nitrides, nitrogen oxides In particular, the composition of the layer contacting the anode is preferably SiOx, AlOx, SiNx, SiON, AlON, GeOx, C to form a stable injection interface layer. In particular, the composition of the layer in contact with the cathode is ideally LiF, MgF2'CaF2'MgF, and NaF. In order to improve the luminous efficiency of the organic EL device of the present invention, it is preferable that at least one side of the organic EL device is sufficiently transparent in the luminous wavelength range of the device. It is also preferable that the substrate is transparent. Using the above-mentioned conductive material, a transparent electrode is set by a method such as vapor deposition or sputtering to ensure predetermined transparency. The light transmittance of the electrodes on the light-emitting surface is set to 10% or more. The substrate is not limited as long as it has mechanical and thermal strength, and it has, for example, a glass substrate and a transparent resin film. Examples of the transparent resin film include polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinyl alcohol, and polyvinyl alcohol. Butyraldehyde, Nylon, Polyetheretherketone, Polyso, Polyetherso, Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, Polyfluoroethylene, Tetrafluoroethylene · ethylene copolymer, Tetrafluoroethylene-hexafluoropropylene copolymerization Materials, polyvinyl chloride trifluoroethylene, polyvinylidene fluoride, polyester, polycarbonate, polyurethane, polyimide, polyetherimide, polypropylene, etc. In order to improve the stability to temperature, humidity, atmosphere, etc. of the organic EL device of the present invention, a protective layer 'may be provided on the surface of the device, or the entire device may be protected by silicone oil, resin, or the like. The formation of each layer of the organic EL element of the present invention can be performed by a vacuum deposition method such as vacuum deposition-26- (22) (22) 200305632, sputtering, plasma, ion implantation, etc., or dry coating, dipping, flow coating, etc. Either of the wet film-forming methods. The film thickness of each layer is not particularly limited, but must be set to an appropriate film thickness. If the film thickness is too thick, in order to obtain a certain light output, a higher voltage must be applied, and the luminous efficiency is deteriorated. When the film thickness is too low, pinholes and the like are generated, and sufficient luminous brightness cannot be obtained even when an electric field is applied. Generally, the film thickness is preferably in a range of 5 nm to 10 μm, and more preferably 10 nm to 0.2 μm. In the case of the wet film formation method, the materials forming each layer are dissolved or dispersed in an appropriate solvent such as ethanol, chloroform, tetrahydrofuran, and dioxane to form a thin film, and the solvent may be any solvent. Further, an appropriate resin or additive can be used to improve the film-forming property of any layer and prevent pinholes in the film. Usable resins are, for example, polystyrene, polycarbonate, polyarylate, polyester, polyamide, polyurethane, polyethylene, polymethyl methacrylate, polymethyl methacrylate, cellulose, etc. Insulating resins and copolymers thereof, photo-conductive resins such as poly-N-vinylcarbazole and polysilane, and conductive resins such as polythiophene and polypyrrole. Examples of the additives include antioxidants, ultraviolet absorbers, and plasticizers. As described above, using the compound of the general formula (1) or (2) of the present invention as the organic thin-film layer of the organic EL device can obtain an organic EL device with high color purity and blue light emission. This organic EL device can be applied to, for example, electrophotography. 'Flat luminous body, photocopier, etc. for flat-panel displays for wall-mounted TVs'! Light source, display board, identification lamp, accessories, etc. of J printer, LCD backlight board or instrument. [Embodiment] -27- (23) (23) 200305632 Next, the present invention will be described in more detail using examples, but the present invention is not limited by these examples. The triplet energy gap and singlet energy gap of the compound are determined as follows. (1) Measurement of triplet energy gap The lowest excited triplet energy level τ 1 is determined. In other words, the photoluminescence spectrum of the sample was measured (10 micromoles / liter EP A (diethyl ether: isopentane: ethanol = 5: 5: 2 volume ratio) solution, 77K, quartz container (cell), Fluorolog II of SPEX Corporation), Calculate the wavelength (light emitting end) of the intersection of the rising tangent on the short wavelength side of the chirped light spectrum and the horizontal axis. This wavelength is converted into energy chirp. (2) Measurement of single-state energy gap Measure the amplitude of excited single-state energy gap. In other words, the toluene solution (10-5 mol / liter) of the sample was used, and the absorption spectrum was measured using a UV-visible light absorber manufactured by Hitachi. Calculate the wavelength (absorptive end) at the intersection of the rising tangent of the long wavelength side of the chirped light spectrum and the horizontal axis. This wavelength is converted into energy chirp. Synthesis Example 1 (Synthesis of Compound (A1)) The synthesis route of Compound (A 1) is as follows.

-28- (24) 200305632 Put 1'bubis (p-bromophenyl) cyclohexane 3.92 g (10 mmol), carbazole 4.0 g (24 mmol), ι8-crown_61.7 g and carbonic acid 29 g of potassium (21 millimoles), 20 ml of o-dichlorobenzene solvent was added, and heated to 20 ° C using a polysiloxane oil bath under a nitrogen stream (TC reaction for 48 hours. After the reaction was completed, the solution was suction-filtered before cooling to obtain a filtrate. Concentrated with an evaporator. 30 ml of methanol was added to the obtained oily substance, and the precipitated solid was filtered under reduced pressure to obtain a gray solid. The solid obtained was recrystallized from benzene to obtain 2.6 g of white crystals (4.6 Ml) (yield 46%). The obtained crystals were confirmed as the target substance (A1) by 90MHz · W-NMR and FD-MS (electric field deionization mass analysis). The measurement results of FD-MS are as follows. FD-MS The singlet energy gap and triplet state of the compound prepared by ca 1 cdf 〇r C 4 2 Η 3 4 N 2 = 5 66, f 〇und, m / z = 5 66 (M +, 1 〇〇) 〇 The energy gap is shown in Table 1.

Synthesis Example 2 (Synthesis of Compound (A4)) The synthesis route of Compound (A4) is as follows.

(Α4) -29-(25) (25) 200305632 except that 1,1.bis (p-bromophenyl) cyclohexane in Synthesis Example 1 was replaced with 1,3-dibromoadamantane, and 3,6-di Phenylcarbazole was substituted for carbazole in Synthesis Example J, and the rest were reacted under the same conditions. The solid obtained was recrystallized with benzene to obtain 1.9 g of white crystals (yield: 25%). The obtained crystal was confirmed to be the object (A4) by 90 MHz W-NMR and FD-MS (electric field deionization mass analysis). : The measurement results of FD-MS are as follows. FD-MS, calcd for C58H46N2 = 7 70, found, m / z = 7 70 (M +, 1 00). The singlet energy gap and triplet energy gap of the prepared compound are shown in Table 1. Synthesis Example 3 (Synthesis of Compound (B 1)) The synthesis route of Compound (B 1) is as follows.

A solution of 5.8 g (24 mmol) of 1-adamantyl magnesium bromide in 20 ml of THF was added dropwise. 4 g (10 mmol) of 3,6-dibromo-N-phenylcarbazole was dissolved in dehydration. In a 50 ml solution of tetrahydrofuran (THF), under nitrogen flow, the reaction was stirred at reflux for 12 hours. After completion of the reaction, 6N hydrochloric acid was added and stirred, and the organic layer was separated, washed with water, and dried over anhydrous magnesium chloride. The obtained extract was distilled off the solvent using an evaporator to obtain a brown solid. The obtained solid was recrystallized from benzene to obtain 1.1 g of pale yellow crystals (yield: 41% -30- (26) (26) 200305632). The obtained crystal was confirmed to be the object (B1) by 90 MHz iH-NMR and FD-MS (electric field deionization mass analysis). The results of FD-MS measurement are as follows. FD-MS, ca 1 cdf 〇r C 3 8 Η 4 1N = 5 11 1, f 〇und, m / 2 = 5 1 1 (M +, 100) 〇 Single-state energy gap and triplet energy of the compound The gap is as follows: 1 m $ 〇 Synthesis Example 4 (Synthesis of Compound (A9)) The synthesis route of Compound (A 9) is as follows.

Add 1,3-bis (p-trifluoromethanesulfonyloxyphenyl) adamantane 3 3g (6mmol), carbazole 1.9g (Ummol), tri (diphenylideneacetone) dipalladium 0.42g (0.5 millimoles), 2-dicyclohexylphosphino-2, (> ^, 1 ^ monomethylamino) biphenyl 0.54g (1 millimoles), potassium phosphate 3.4g (i6 millimoles ) Suspended in 23 ml of toluene, heated under reflux for 8 hours and 30 minutes under an argon atmosphere. The reaction solution was cooled to room temperature, added with water and extracted with dichloromethane, washed with water, and dried over anhydrous sodium sulfate. After the organic solvent was distilled off under reduced pressure, 15 ml of ethyl acetate was added, and the precipitated crystals were filtered and washed with ethyl acetate to obtain 1.9 g of crystals (yield: 58%). The obtained crystal was identified as the target compound (A9) by 90MHz j-NMR and FD-MS (electric field deionization mass analysis) -31-(27) 200305632. The measurement results of FD-MS are as follows. FD-MS, calcd for C46H38N2 = 618, found, m / z = 618 (M +, 100). The singlet energy gap and triplet energy gap of the compound prepared are shown in Table 1. Energy gap (eV) Triplet energy gap (eV) Synthesis example 1 Α1 3.6 3. 1 Synthesis example 2 Α4 3.1 2.8 Synthesis example 3 Β 1 3. 1 2.8 Synthesis example 4 Α9 3.6 3.1 Example 1 25mmx75mmxl.lmm thick A glass substrate (made by ZIOMATIC) containing an ITO transparent electrode was ultrasonically washed in isopropyl alcohol for 5 minutes, and then washed with UV ozone for 30 minutes. The rinsed glass substrate containing the transparent electrode was mounted on a substrate holder of a vacuum evaporation device. First, a 60 nm thick N, N'-double (N, N'- Diphenyl-4-aminophenyl) -N, N-diphenyl-4,4'-diamino-1,1'-biphenyl film (TPD232 film) to cover the above-mentioned transparent electrode. The TPD 23 2 film functions as a hole injection layer. Next, a 4,4'-bis [N- (l-naphthyl) -N-phenylamino group] -32- (28) (28) 200305632 biphenyl film (NPD film) was formed on the TPD 232 film to a thickness of 20 nm. ). The NPD film has a function of a hole injection layer. On the NPD film, a film of the above-mentioned compound (A1) was formed to a thickness of 40 nm by evaporation. At this time, the following compound (D1) was vapor-deposited at a weight ratio of (A1) :( D1) of 40: 3. In order to generate blue light, the compound (D1) is a light-emitting molecule having a low singlet energy of 2.79 eV. The mixed film of the compounds (A 1) and (D 1) has the function of a light emitting layer. On the film, a BAlq (Me is methyl) film described below was formed to a thickness of 20 nm. The BAlq film functions as an electron injection layer. Next, Li (Li source: SAY GETTER company) and Alq, which are reducing dopants, were subjected to binary evaporation to form a second electron injection layer (cathode) Alq: Li film (film thickness: 10 nm). The Alq: Li film was vapor-deposited with metal A1 to form a metal cathode, and an organic EL element was manufactured. This element obtained a high-efficiency blue light emission with a luminance of 116 cd / m2 and a luminous efficiency of 4.9 cd / A at a DC voltage of 5.0 volts. The chromaticity coordinates are (0.15, 0.16), and the color purity is high.

BAlq -33 (29) (29) 200305632 Examples 2 to 4 Except using the compound of Table 2 instead of the compound (AJ) of Example 1, an organic EL device was also prepared, and the DC voltage, light emission brightness, light emission efficiency, and The emission color and color purity are shown in Table 2. Comparative Example 1 An organic el device was produced in the same manner except that the following compound B Cz, which is a conventionally known compound, was used instead of the compound (A1) of Example 1. The results were also measured for DC voltage, light emission brightness, light emission efficiency, light emission color, and color purity. As shown in table 2.

Comparative Example 2 Except that the following compound (C2) of Japanese Patent Laid-Open No. 2001-288462 was used instead of the compound (A1) of Example 1, an organic EL element was produced in the same manner, and DC voltage, light emission brightness, light emission efficiency, and The emission color and color purity are shown in Table 2. -34- (30) 200305632

(C2) Table 2 Voltage of the organic main material of the light-emitting layer (V) Luminous brightness (cd / m2) Luminous efficiency (cd / A) Luminous color chromaticity coordinates Example 1 A1 6.1 116 4.9 Blue (0.15, 0.17) Example 2 A3 5.2 1 56 5.6 Blue (0.14, 0.16) Example 3 A4 6.2 172 5.1 Blue (0.15, 0.17) Example 4 B 1 6.7 122 4.8 Blue (0.14, 0.16) Comparative Example 1 BCz 8.5 70 2.4 Blue (0.14, 0.16) ) Comparative Example J 2 C2 6.5 65 2.6 Blue (0.14, 0.16) As shown in Table 2, compared to the conventional compounds BCz and (C2) of the comparative example, the organic EL device using the compound of the present invention is a low voltage drive -35 -(31) 200305632, and can get high efficiency blue light emission. The compound of the present invention is wide, so the light-emitting molecules with a wide mixed energy gap in the light-emitting layer can be used in Example 5. 25mm > < 75mmxl.lmm thick ITO-containing transparent electrode plate, washed with ultrasonic in isopropyl alcohol for 5 minutes After that, take UV 30 minutes. On the substrate holder of the glass substrate vapor deposition device containing the transparent electrode after washing, a copper phthalocyanine film (CuPc film described below) with a thickness of 10 nm was formed on the surface of the transparent electrode to cover the electrode. This CuPc film functions as a hole injection layer. A 4,4′-bis [N- (N-aniline) biphenyl film (a-NPD film described below) with a thickness of 30 nm is formed on the CuPc film. The α- functions as a hole transporting layer. ^-The main material of the above-mentioned compound (A 1) is vapor-deposited on the NPD film to form a light-emitting layer film and a photoluminescence Ir metal complex dopant _ (2-) Ir (the following Ir (ppy) 3). Ir (ppy) in the light-emitting layer is 5% by weight. The film has the function of a light-emitting layer. The shape of the film is nano (1,1'-bisphenyl) -4-ol) bis (2 -Methyl-8-aluminum film (BAlq film). The BAlq film has an aluminum hole complex layer formed of 8-hydroxyquinoline aluminum complex film on the film with a hole barrier layer). The Alq film has a function of an electron injection layer. Then, a halogenated alkali metal LiF of 0.2 nm was used, followed by evaporation of 150 nm of aluminum. The Al / LiF has the function of a cathode. Glass-based ozone-washed, which emits light due to its energy gap, was formed as described above, and the film was formed on a vacuum. The film was transparent as described above, and the 1-naphthyl) -NPD film had a thickness of 30 nm. At the same time, the concentration of phenyl 0 is higher than that of hydradin 3, and the film thickness is 10 quinolinol). This film (the following post-evaporation thick millimeter EL element -36- (32) 200305632 50 rugged parts were subjected to a current test 'with a voltage of 5.5 V and a current density of 0.22 mA / cm2, a luminous efficiency of 舄 43 8cd can be obtained / A, green luminescence with a luminous brightness of 98 cd / m2, and a chroma block (0,32).

Example 6 Except that the compound (A9) was used instead of the main material compound (A1) of the light-emitting layer of Example 5, an organic El device was also produced, and the voltage, current density, light emission brightness, light emission efficiency, and chromaticity were also measured. The results are shown in the table. 3 shown. Comparative Example 3 An organic EL device was prepared in the same manner except that the above-mentioned compound BC z of a known compound was used instead of the main material compound (A1) of the light-emitting layer of Example 5. (33) 200305632 The voltage, current density, light emission brightness, and light emission were also measured. The efficiency and chromaticity results are shown in Table 3. Comparative Example 4 Except that the following compound (A-10) of U.S. Patent Publication 2002-0028329A1 was used instead of the main material compound (A1) of the light-emitting layer of Example 4, an organic EL device was also fabricated, and the DC voltage, current density, and The luminous intensity, luminous efficiency, and chromaticity are shown in Table 3.

A-10 The main material of the surface emitting layer Triplet energy gap (eV) Single state energy gap (eV) Voltage (V) Current density (mA / cm2) Luminous brightness (cd / m2) Luminous efficiency (cd / A) Chroma Coordinates (x, y) Implementation_ 5 Α1 3.1 3.6 5.8 0.22 98 43.8 (0.32,0.62) Implementation 6 Α9 3.1 3.6 5.4 0.22 102 45.7 (0.32,0.61) Comparative Example 3 BCz 2.8 3.6 5.4 0.31 101 32.6 (0.32, 0.61) Comparative Example 4 A-10 3.1 3.7 5.9 0.32 100 31.8 (0.32, 0.61) As shown in Table 3, compared with the conventional compounds (BCz, A-10) of Comparative Examples 3 and 4, The organic EL element can obtain high-efficiency green light emission. In addition, since the compound of the present invention has a wide energy gap, light-emitting molecules having a wide energy gap can be mixed in the light-emitting layer to emit light. Example 7 -38- (34) (34) 200305632 A 25 mm x 75 mm x 0.7 mm thick glass substrate containing a transparent ITO electrode was subjected to ultrasonic washing in isopropyl alcohol for 5 minutes' and then washed with UV ozone for 30 minutes. The washed glass substrate containing the transparent electrode was mounted on a substrate holder of a vacuum evaporation device. First, a copper phthalocyanine film (CuPc film) with a thickness of 10 nm was formed on the surface forming the transparent electrode to cover the transparent electrode. The CuPc film functions as a hole injection layer. Next, an a-NPD film with a thickness of 30 nm was formed on the CiiPc film. The a-NPD film functions as a hole transporting layer. The compound (A1) having a thickness of 30 nm was deposited on the NPD film to form a light-emitting layer film. At the same time, Ir bis [(4,6-difluorophenyl) -pyridine-N, C2 '] picolinate (hereinafter FIrpic) was added. The concentration of FIrpic in the light-emitting layer was 7% by weight. The film functions as a light emitting layer. A BAlq film having a thickness of 30 nm was formed on the film. The BAlq film functions as a hole injection layer. Then, a halogenated alkali metal LiF having a film thickness of 0.2 nm was evaporated, and aluminum having a thickness of 150 nm was vapor-deposited. The Al / LiF functions as a cathode. An organic EL element was produced as described above. The device was subjected to a current test, and a blue light emission with a luminance of 10 4 c d / m2 and a luminous efficiency of 15.4 cd / A was obtained at a voltage of 7.2 V and a current density of 0.68 mA / cm2, and the chromaticity coordinates were (0.17, 0.38).

Example 8 -39- (35) 200305632 Except that the compound (A9) was used instead of the main material compound (A1) of the light-emitting layer of Example 7, an organic EL device was also produced, and the voltage, current density, light emission brightness, light emission efficiency, and Chroma. The results are shown in Table 4. Comparative Example 5 An organic EL device was fabricated in the same manner except that the conventional compound BCz was used instead of the main material compound (A1) of the light-emitting layer of Example 7. The voltage, current density, luminous brightness, luminous efficiency, and chromaticity were also measured. 4 shown. Table 4 The triplet energy gap (eV) of the main material of the light-emitting layer, the singlet energy gap (eV), the voltage (V), the current density (mA / cm2), the luminous brightness (cd / m2), the luminous efficiency (cd / A), and the chromaticity coordinates ( x, y) Example 7 A1 3.1 3.6 7.2 0.68 104 15.4 (0.17, 0.38) Example 8 A9 3.1 3.6 7.1 0.66 99 15.1 (0.17, 0.38) Comparative Example 5 BCz 2.8 3.6 7.6 1.09 99 9.15 (0.17, 0.37) such as As shown in Table 4, the organic EL device using the compound of the present invention was driven at a low voltage with respect to the conventional compound BCz of the comparative example, and blue light emission with high light emission efficiency was obtained. In addition, the compound of the present invention has a wide energy gap, so mixing a light-emitting molecule with a wide energy gap in a light-emitting layer makes it possible to use the light-emitting industry as described above in detail. The general formula (1) of the present invention is used. Or, for an organic electroluminescent device material composed of a compound represented by (2), an organic electroluminescent device with high luminous efficiency and color purity and blue light emission can be obtained from -40-(36) 200305632. Therefore, the organic electroluminescent device of the present invention is very suitable as a light source for various electronic devices.

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Claims (1)

(1) 200305632 Patent application scope 1. A material for an organic electroluminescent device, which is characterized by a compound represented by the following general formula (1) or (2), (C z-) n L (1 ) Cz (-L) m (2) [where Cz is a group formed by a compound having a carbazole skeleton represented by the following (a) 'may be substituted, and L is a substituted or unsubstituted carbon number of 5 to 30 ring courtyard group 'or an aromatic ring group having 6 to 30 carbon atoms, substituted or unsubstituted, represented by (b) below, η and m are integers of 1 to 3, respectively; (X is a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 40 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms Aryloxy) (B) (P is an integer from 1 to 4). 2. The material for organic electroluminescent device -42-(2) 200305632 according to item i of the patent application range, in which the compounds represented by the above general formulae (3) ~ (1 1) 1) or (2) The compounds shown by any of the above are described as Cz— L —Cz (n = 2)-(-3-). Cz—Cz—Cz 1 (n = 3) (4) L Cz—L—Cz ~ Cz (n = 3) (5) Cz—Cz—Cz —B (n = 3) (6) L — Cz— L (m = 2) (7) E-L—Cz • (m = 2) (S) L —Cz—L 1 (m = 3) (9) B—L—L—Cz—L (m = 3) (10) Cz—L—L—L (m = 3) (11) 3. If the scope of patent application帛 lx ^ Material for Organic Electro-Optical Excitation Optical Elements' wherein the single-state energy gaps of the compounds of the above-general formula (1) or (2) are 2.8 to 3.8 eV, respectively. 4. For example, the material for organic electro-optic light-emitting device of item 1 of the patent application ′ where the triplet energy gaps of the above-general formulae (1) and (2) are 2.5 ~ 3.3 eV, respectively. 5. An organic electro-excitation light element, which is an organic electro-excitation light element in which an organic thin-film layer composed of a single layer or multiple layers is sandwiched between a cathode and an anode. Contains the material # of the organic electroluminescent device as described in the first patent application scope. 6 · —An organic electro-optical light-emitting element, which is an organic electro-optical light-emitting element with an organic thin film layer composed of a single layer or multiple layers between a cathode and an anode, and is characterized in that the light-emitting layer contains the first item in the scope of patent application Organic Electro-Excitation-43- (3) (3) 200305632 Materials for Optical Elements. 7. An organic electroluminescent device, which is an organic electroluminescent device with an organic thin film layer composed of a single layer or multiple layers between a cathode and an anode, and is characterized in that the light-emitting layer contains Material for organic electroluminescent device. 8. An organic electroluminescence light element, which is an organic electroluminescence light element in which an organic thin film layer composed of a single layer or multiple layers is sandwiched between a cathode and an anode. Materials for organic electroluminescent devices. 9. An organic electroluminescence light element, which is an organic electroluminescence light element in which an organic thin film layer composed of a single layer or a plurality of layers is sandwiched between a cathode and an anode, and is characterized in that the electron transport layer contains the first item in the scope of patent application Materials for organic electroluminescent devices. 1 0 · — An organic electro-optical light-emitting element, which is an organic electro-optical light-emitting element with an organic thin-film layer composed of a single layer or multiple layers sandwiched between a cathode and an anode. The material for an organic electroluminescent device according to item 1. 1 1 · The organic electroluminescent device according to item 5 of the scope of the patent application, wherein the material for the organic electroluminescent device is an organic main material. 1 2. The organic electroluminescent device according to item 5 of the patent application, wherein at least one of the electrodes has an inorganic compound layer between the electrode and the organic thin film layer. 1 3 · The organic electro-excitation light-emitting device according to item 5 of the scope of patent application, which emits light through triplet excitation or multiple-state excitation. 1 4 · If the organic electro-optical light-emitting element of the fifth item of the patent application, -44- 200305632 (4) is blue light emission. 200305632 Lu, (a) (b) The designated representative of this case is: None. Brief description of the representative symbols of the elements in this case: Μ 柒. If there is a chemical formula in this case, please reveal the chemical formula that can best show the characteristics of the invention: